Properties

Label 2.9.ae_h
Base field $\F_{3^{2}}$
Dimension $2$
$p$-rank $2$
Ordinary yes
Supersingular no
Simple yes
Geometrically simple no
Primitive yes
Principally polarizable yes
Contains a Jacobian yes

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Invariants

Base field:  $\F_{3^{2}}$
Dimension:  $2$
L-polynomial:  $1 - 4 x + 7 x^{2} - 36 x^{3} + 81 x^{4}$
Frobenius angles:  $\pm0.0656128605321$, $\pm0.601053806135$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{-3}, \sqrt{-5})\)
Galois group:  $C_2^2$
Jacobians:  $6$
Isomorphism classes:  6

This isogeny class is simple but not geometrically simple, primitive, ordinary, and not supersingular. It is principally polarizable and contains a Jacobian.

Newton polygon

This isogeny class is ordinary.

$p$-rank:  $2$
Slopes:  $[0, 0, 1, 1]$

Point counts

Point counts of the abelian variety

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $49$ $6321$ $470596$ $42028329$ $3500716849$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $6$ $80$ $642$ $6404$ $59286$ $530486$ $4778934$ $43058564$ $387442578$ $3486722000$

Jacobians and polarizations

This isogeny class contains the Jacobians of 6 curves (of which all are hyperelliptic), and hence is principally polarizable:

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{3^{6}}$.

Endomorphism algebra over $\F_{3^{2}}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-3}, \sqrt{-5})\).
Endomorphism algebra over $\overline{\F}_{3^{2}}$
The base change of $A$ to $\F_{3^{6}}$ is 1.729.abs 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-5}) \)$)$

Base change

This is a primitive isogeny class.

Twists

Below are some of the twists of this isogeny class.

TwistExtension degreeCommon base change
2.9.e_h$2$2.81.ac_acz
2.9.i_bi$3$2.729.adk_fao
2.9.ai_bi$6$(not in LMFDB)

Below is a list of all twists of this isogeny class.

TwistExtension degreeCommon base change
2.9.e_h$2$2.81.ac_acz
2.9.i_bi$3$2.729.adk_fao
2.9.ai_bi$6$(not in LMFDB)
2.9.a_c$6$(not in LMFDB)
2.9.e_h$6$(not in LMFDB)
2.9.a_ac$12$(not in LMFDB)